I used Turbo Tax as an estimator for 2014 & 2015, but did not file through you yet. I am making the switch for 2016, how do I get rid of old inaccurate info from 14-15

There is a tricky way to clear out transferred info in the Online version.  But doing this will also clear out all your entries.  Go to My Account > Tools > Transfer from your computer > Continue > then Continue without transferring.